.... the Alnico ring is a cylinder inside the voice coil ....
Why indeed? Just another one of the audiophile myths.
I think some people like the sound of a partially demagnetized speaker, you know, more bass from a D130.
David S.
Why indeed? Just another one of the audiophile myths.David S.
Thanks..... on diyaudio I always find the answers...
Alnico was fine with 20 watt amplifiers but anything in the hundreds can easily and instantly drop the sensitivity by 2 or 3 dB with a good LF blast.
David,Alnico was fine with 20 watt amplifiers but anything in the hundreds can easily and instantly drop the sensitivity by 2 or 3 dB with a good LF blast.
Lots of white papers at the Harman site on this.
David S.
I am aware of the well known phenomenon of remagnetizing services for old Alnico, as well as speaker cables that cost over $10,000.Not reference material but I have seen it done first hand. At JBL we had a Crown D600 to drive any speaker being tested on the outdoor asphalt pad. Greg Timbers showed me once how he could pull the input on it (or maybe it was via the sine generator) and blast the unit with hum for a second and then run the curve again to see what the sensitivity had become (midband level). He was trying to drop the sensitivity/raise the Q of a particular driver and, after a couple of trys got what he wanted.
Not a thermal thing but more to do with its resistance to demagnetization related to its operating point. It was a bit random because you don't know where the signal would end up with your short blast, positive or negative.
I distinctly remember both Greg's approach, and seeing the curve difference. I thought this was a well known phenomenon and that people offered remagnetizing services?
On the other side of the fence there is always ferrite losing sensitivity due to extreme cold. I've heard of speaker shipments that sat out all night in the far flung regions of Minnesota. They were returned by customers with complaints of low sensitivity.